Feminine care absorbent articles are often used to collect and retain body fluids, liquids, or exudates containing menses or blood. In the context of such products, comfort, absorbency, and discretion are three main product attributes and areas of concern for the wearer. In particular, wearers are often interested in knowing that such products will absorb significant volumes of menses exudates in order to protect their undergarments, outergarments, or bedsheets from staining, and that such products will help them avoid the subsequent embarrassment brought on by such staining. Wearers are also interested in using products that cannot be seen or felt through their undergarments.
Feminine care absorbent articles, such as sanitary napkins, pads and pantiliners, typically include at least one or more absorbent layers enclosed between a body-facing, liquid permeable topsheet layer and a garment-facing liquid impermeable backsheet layer. The edges of the topsheet and backsheet layers are often bonded together at their periphery to form a seal around the article to thereby contain the absorbent layers and any exudates received into the article through the topsheet. In use, such articles are typically positioned in the crotch portion of an undergarment for absorption of bodily exudates, and are held in place via adhesive strips positioned on the undersurface of the articles (facing the garment). Some of these articles also include wing-like structures for wrapping about the user's undergarments to further secure them to a user's underwear. Such wing-like structures (also known as flaps or tabs) are frequently made from lateral extensions of the topsheet and backsheet layers.
For many women, it is entirely routine to periodically view their feminine care absorbent articles during use, so as to monitor the appearance and spread of a menses insult (so as to avoid leakage throughout the day). For some women, a concern or cause of emotional discomfort with conventional feminine care absorbent articles is the expanding appearance of a menses insult in the article, and specifically, the spread of the menses stain to the side edges of a product. While many women often do not mind seeing a targeted stain in the center of a pad, and then change the pad accordingly, some women prefer not to see an extensive stain, other than the centralized insult stain. Obviously, the leakage of fluids when using such articles, particularly from around the side edges of the articles, is universally a cause of emotional concern. Such leakage may occur in the narrower product dimension along the longitudinally directed side edges, or along the wing or flap areas. Product leakage may lead not only to embarrassment for the user, but also to a general loss of confidence in use of the articles.
Various attempts have therefore been made to incorporate chemistry or structures into feminine care pads to separate staining, direct staining, target staining, mask staining or discolor menses staining; to make more efficient use of as much of an absorbent product as possible; and to reduce or prevent leakage. Such structures include embossed walls or channels, printed target areas, polymeric or other liquid impermeable barrier walls, and the like. However, such attempts have not been completely successful at eliminating or addressing the leakage problem, or reducing user concerns over staining, should it occur.
Attempts have also been made to chemically alter and separate components of menses along the depth direction of a pad, and thus reduce the mental impact of a possible stain, should menses strike through an absorbent layer to the bottom of a pad. For example, U.S. Pat. No. 3,124,135 to Olson, discloses the use of salts on a pad's interior layers (salt layer sandwiched between absorbent core layers and having the same lateral dimensions of the absorbent layers), so as to decolorize menses by precipitating the darker colored hemoglobin of the menses, as fluid travels in the depth direction of the pad. Such decolorizing allows almost clear menses liquid to flow to various portions of lower absorbent layers and away from the precipitated hemoglobin. Such decolorizing also allows clear menses liquid to potentially flow through a lower absorbent layer to the bottom of a pad, thereby reducing the occurrence of a visible stain at the bottom of a pad. The Olson reference highlights the stiffness produced in a pad as a result of the interior salt-containing layers, and offers a pad softening-solution, by use of polyethylene glycol (hereinafter PEG) as an additional element with the impregnated salt elements on the interior layers of a pad. However, even with such salt and PEG combinations, the placement of this agglomeration chemistry on, or immediately near the absorbent layers, and having the same lateral dimensions as the absorbent layers (along the depth (z) axis), can lead to the blocking of absorbency pathways in an article. Possible leakage may then result from the redirected fluid. Further, the Olson reference does not address staining that results from pad leakage off of the pad top surface, either as a result of fluid flow or saturation of a subjacent absorbent layer. Nor does the Olson reference address the concern of consumers that would rather limit their viewing of a stain in a pad, when viewing a pad from the topsheet layer surface. U.S. Patent Publication No. 2012/0165773 to Nakashita, et al. also describes placement of chemistry within the core layer. A further reference which describes an alternative technique for filtering using a “depth filter” is U.S. Pat. No. 6,350,711 to Potts, et al. Still another reference which describes the use of specific salts to remove colored substances from aqueous fluids is U.S. Patent Publication No. 2012/0215192 to Corbellini, et al. However, there is still a need to lessen leakage, and to alter the stain-producing fluid off of a feminine hygienic pad top surface, so as to lessen the mental impact of a menses insult (and potential leakage stain) for pad users, without interfering with the functioning of a product's absorbent layers; there is also a need for such alteration of the stain-producing fluid without impacting product “feel” that may be impacted by the addition of salts; and there is also a need for a pad which limits staining potential as well a consumer's view of a stain within the pad.
Numerous absorbent structures have also been developed for capturing and retaining voluminous menses exudates released by women during their monthly cycles. In this regard, the designs of such absorbent pads and pantiliners have been refined over time, so as to make their usage more comfortable (physically and emotionally) to consumers. As absorbent technology has advanced, superabsorbent polymer chemistry and substrate layering designs have been developed, enabling manufacturers to produce feminine absorbent products with progressively thinner configurations. As a result, feminine hygiene sanitary napkins, pads, and liners have become significantly thinner and more absorbent, so as to impart both comfort and a certain inconspicuousness to a wearer. For the most part, such thinner products have provided the users and surrounding third parties with the impression that the user is not wearing any form of menses protection in her undergarments.
Generally, feminine hygiene sanitary napkins, pads, and liners predominantly distribute menses laterally and longitudinally, and, when they leak, predominantly leak off the side edges (longitudinally directed sides, front, and back) rather than through the pad bottom. This leakage distribution is driven in part by not-so-close pad body fit, due to attachment to underwear or panties, and the pad construction. These pads are typically less than ¼ inch thick, have an impervious layer to impede menses and air movement through the pad, and utilize specific distribution materials to drive lateral and longitudinal distribution. Modern pads also contain superabsorbent that can interfere with the distribution of menses within the pad. The use of superabsorbent materials in core layers can lead to gel blocking that interferes with maximized fluid absorption.
Even with these advancements in absorbency, however, consumers continue to experience some leakage, typically from fluid run-off from the topsheet surface. Such run-off is often the result of various “structural” and “action-based” root causes, which cause soiling of user garments or bedding. For example, structural causes may include impeded absorbency pathways or inability to handle fluid surges. Further, consumer movements during their daily activities may cause menses exudates to leak off of the absorbent article. Therefore, despite the development of many different absorbent technologies and structural designs, product leakage and the resulting stains caused from such leakage continue to concern potential users of such products. Further, mere adaptation of older decolorizing technology to modern pad structures is not adequate to prevent locally overwhelming the decolorizing technology, as it does not account for interference from modern superabsorbents (superabsorbent competes with the decolorizing technology for the menses), lack of adequate surface area, and modern day pad menses distribution. A need therefore exists for pad constructions that prevent lateral and longitudinal distribution of the red stain of menses.
Certain sensors or condition change indicators are known for use with feminine care absorbent articles and other types of absorbent articles, to notify a user or caregiver of the impending need to change such article as a result of a change in condition. Such devices may assist in providing consumers with calmed emotional states, knowing that the devices are actively communicating impending product failure or body states. Such indicators can be seen for example in U.S. Patent Publication Nos. 2003/0130631 to Springer and 2007/0055210 to Kao. While such devices are focused primarily on preventing leakage or staining, or the onset of some other condition by limiting user wear time, such devices do not assist in altering potential staining, should leakage actually occur. There is therefore a further need for such products which would reduce consumer emotional concerns of such staining, and the embarrassment that might accompany such staining if it were to occur.
As previously described, certain chemistry for the decolorizing of blood stains on absorbent articles is known. For example, colorant changers, neutralizers or decolorizing compositions are described in U.S. Patent Publication Nos. 2008/0277621 to MacDonald, 2009/0061718 to Seidling, and 2009/0062764 to MacDonald, WO2009133518 to Cunningham, U.S. Pat. No. 6,730,819 to Pesce, U.S. Pat. No. 7,105,715 to Carlucci, and U.S. Pat. No. 3,124,135 to Olson, U.S. Patent Publication No. 2011/0004174 to Carlucci, and WO2011027295 to Corbellini, each of which are hereby incorporated by reference in their entirety. However, such chemistries are often difficult to place uniformly on a product surface, or to manipulate into a high enough surface area. Further, such chemistries may often result in a heavier, stiffer, and a subsequently more uncomfortable feeling article. Finally, such chemistries may result in menses color alterations that are less desirable to a consumer. Therefore, even with these available chemistries for decolorizing, there is a further need for absorbent structures which utilize barrier structures and decolorizing chemistry to reduce the severity/appearance of menses staining of both a user's pad, and a user's garments or bedding. There is also a need for absorbent articles which reduce a consumer's concern over any stain that might occur, as well as articles which more efficiently use absorbent systems to take up retained liquids.